15kHz with multiplexing
Dependencies: FastAnalogIn mbed
Diff: main.cpp
- Revision:
- 0:d83ac315a24c
- Child:
- 1:8e7e9ef6b0bd
diff -r 000000000000 -r d83ac315a24c main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Fri Feb 17 20:37:32 2017 +0000 @@ -0,0 +1,106 @@ +#include "mbed.h" +#include "FastAnalogIn.h" + + +FastAnalogIn ain(p20); //Analog Input to PDmux +DigitalOut LEDout(p8); //5V output to LED mux +DigitalOut LEDmux0(p9); //s0 +DigitalOut LEDmux1(p10); //s1 +DigitalOut LEDmux2(p11); //s2 +DigitalOut LEDmux3(p12); //s3 + +DigitalOut PDmux0(p14); //s0 +DigitalOut PDmux1(p15); //s1 +DigitalOut PDmux2(p16); //s2 +DigitalOut PDmux3(p17); //s3 + + + +double alpha; //dummy variable for ADC + + +int main() +{ +// double ADCtime=.000000116; //1.6 us + double time=.000029; // ~15kHz +// double time=.0000029; //100 kHz +// double time=.003; + + //counters for various while loops + int mPD=0; + int nPD=0; + int mLED=0; + int nLED=0; + int pd=0; + int i=0; + + //boolean bits for multiplexing + LEDmux0=0; + LEDmux1=0; + LEDmux2=0; + LEDmux3=0; //MSB is always 0 + PDmux0=0; + PDmux1=0; + PDmux2=0; + PDmux3=0; //MSB is always 0 + + + //while loop that runs continously through code to constantly give measuremtn while MCU is on + while(1) { + + + //loop to mux through the 8 photodiodes + while(pd<8) { + //loop will take 5 measurements for the selected LED/PD combo + while(i<5) { + LEDout = 1; + alpha=ain.read(); + wait(time); + + LEDout = 0; + alpha=ain.read(); + wait(time); + i++; + } + i=0; + + PDmux0=!PDmux0; //flip LSB + + //flips 2nd bit every other cycle + if (mPD==1) { + PDmux1=!PDmux1; + mPD=0; + } else { + mPD++; + } + + //flips 3rd bit after every 4th cycle + if (nPD==3) { + PDmux2=!PDmux2; + nPD=0; + } else { + nPD++; + } + pd++; + } + pd=0; + + //same multiplexing code above, but for LEDs + LEDmux0=!LEDmux0; + + if (mLED==1) { + LEDmux1=!LEDmux1; + mLED=0; + } else { + mLED++; + } + + if (nLED==3) { + LEDmux2=!LEDmux2; + nLED=0; + } else { + nLED++; + } + + } +}